Selling gets a tax free gain and allows you to be more liquid; keeping it allows you to have once in a lifetime cheap debt and have that leverage on an appreciating asset. 

Or paying off my debt, while I provide them with a nice house to live in instead of an apartment. 

@Daniel Tanasa   Unfortunately that is not correct when it comes to mortgage debt.

Mgt, Landscape/Snow, tax, insurance, utility then debt service. 

The property jumped another 100k less than a year after the sell as well as rents went up to support what would have been the new monthly debt if I refinanced and held. 

Two views of ownership; owning the equity,  owning the debt. 

The math behind Real Estate is not that complicated, Revenue - expenses and debt service = cash flow. 

could it service the debt on $1m?

Deduct NEW property taxes after you buyDeduct home insurance costsDeduct maintenance percentage, typically 10%Deduct vacancy+tenant nonperformance percentage(we recommend 5% for Class A, 10% Class B, 20% Class C, good luck with Class D)Deduct whatever dollar/percentage of cashflow you wantNow, what you have left over is the amount for debt service.Enter it into a mortgage calculator, with current interest rate for an investment property, to determine your maximum mortgage amount.Divide the mortgage amount by either 75% or 80%, depending on the required down payment percentage - this is your tentative price to offer.If the property needs repairs, you'll want to deduct 110%-120% of the estimated repairs from this amount.Be sure to also research the ARV and make sure it's 10-20% higher than your tentative purchase price.As long as the ARV checks out, this is the purchase price to offer.It is probably significantly below the asking price.

I literally laughed through the phone at his suggestion, because I was broke, in debt, and in every way and unqualified borrower, and the lending environment in 2012 was probably stricter than it had been since the invention of the 30yr mortgage.